JP2017500238A - Device for controlling vehicle tire pressure - Google Patents

Abstract

An apparatus (10) for supplying pressurized air to a rotating pneumatic tire is disclosed. The device includes a pump (48, 50, 58) that rotates with the tire in use and supplies pressurized air to the tire when the pump is activated. A pump drive system is provided to activate the pump when the tire pressure is lost. The pump drive system includes a connecting rod (52) that is rotationally connected to the tire and an eccentric member (32) that rotates with the rod when the pump is not active. When the eccentric member is prevented from rotating with the rod, it activates the pump. The relative rotation between the rod and the eccentric member drives the pump to supply pressurized air to the tire. An electromagnetic clutch having a first plate (26) that cannot rotate and a second plate (36) that rotates together with the eccentric member is provided. When the clutch is engaged to prevent rotation of the second plate and the connecting rod, the first plate is electromagnetically connected to the second plate.

Description

  The present invention relates to a built-in device for maintaining the pressure of a rotating element, such as a vehicle tire.

  Devices for maintaining vehicle tire pressure are disclosed in US Pat. The device is mounted on a vehicle wheel, each containing a suspended fixed counterweight, while the other parts of the device usually rotate with the wheel. When the tire on the vehicle wheel loses pressure, this part is fixed because a part of the device is connected to the counterweight by a pneumatic friction clutch. The relative movement between the fixed part and the other part of the device is used to drive a pump that pressurizes the tire to the desired pressure.

US Pat. No. 7,013,931 PCT Application No. PCT / IB2013 / 054732 (published as pamphlet of International Publication No. 2014/009822)

  The present invention seeks to provide a simple and cost effective improvement over such prior devices.

According to the invention, a device for supplying pressurized air to a rotating pneumatic tire is provided, which device comprises:
(A) a pump that rotates with the tire during use and supplies pressurized air to the tire when the pump is activated;
(B) A pump drive system for starting the pump at the time of pressure loss in the tire,
(C) a first portion that is rotationally connected to the tire;
(D) a second part that rotates with the first part when the pump is not acting and activates the pump when rotation with the first part is prevented, the relative between the first and second parts A second portion, the rotation driving the pump to supply pressurized air to the tire;
(E) An electromagnetic clutch including a first plate that cannot rotate and a second plate that rotates together with the second portion, and the first plate is electromagnetically connected to the second plate when the clutch is engaged. An electromagnetic clutch for preventing rotation with the first plate and the second portion;
A pump drive system including:
including.

  The clutch is preferably a hysteresis clutch.

  In one form, the coil is supported by one of the plates, a battery pack and a switch for connecting the battery pack to the coil so that current flows through the coil are provided.

  In another form, the device induces a current in a closed circuit constituted by a coil supported by one of the plates, a magnet supported by the other of the plates, and rotation of the coil in close proximity to the magnets. And a switch for short-circuiting the coil.

  For a better understanding of the present invention and to show how it can be implemented, the invention will now be described by way of non-limiting examples with reference to the accompanying drawings.

1 is a perspective view of a pair of vehicle wheels equipped with a device according to the present invention on a wheel hub. FIG. It is sectional drawing of a pair of wheel and apparatus of FIG. FIG. 3 is an enlarged detailed cross-sectional view of the hub and apparatus of FIGS.

  Referring to the drawings, an apparatus according to the present invention is generally designated by the reference numeral 10 and is shown in use to supply fluid in the form of compressed air to a rotating element in the form of a pneumatic tire in use.

  The device 10 is shown in FIGS. 1 and 2 as being integrated into the hub 12 of a pair of wheels 14. Each wheel 14 includes a rim 16 on which a pneumatic tire 18 is mounted. The rim 16 is attached to the hub 12 by a wheel nut 20. In the example shown, the wheel is not driven, for example for a large vehicle trailer. In FIG. 1, another hub 12.1 is shown. The hub 12.1 shares a common shaft 22 with the hub 12.

  Referring to FIG. 3, the hub 12 is rotatably supported on the fixed hollow shaft 22 by a pair of wheel bearings 24. A screw thread is formed at the end of the shaft 22, and the hub 26 and the wheel bearing 24 are held at predetermined positions on the shaft 22 by attaching a stator 26 to the screw thread. In a preferred embodiment, the stator 26 is mounted on the shaft 22, such as using additional or other mounting means that stabilize the stator and ensure accurate axial orientation. Due to the mounting on the shaft 22, the stator 26 does not rotate with the hub 12 and is therefore stationary.

  The pump shaft 28 is disposed at the end of the shaft 22, and the head 30 of the pump shaft 28 is held by the stator 26 at a predetermined position of the recess at the end of the shaft 22. The pump shaft 28 extends outwardly from the wheel, i.e., to the left from the stator 26 as shown in FIGS. 2 and 3 and is in a fixed state with the shaft 22 and the stator 26. The eccentric member 32 is supported by the pump shaft 28 and rotates on the roller bearing 34 around the pump shaft. The eccentric member 32 includes a rotor 36, and a plurality of AC generator coils 38 are supported on the rotor 36. The coils are at a radial distance from the same rotational axis as the plurality of AC generator magnets 40 supported by the stator 26. When the hub 12 and the wheel 14 rotate, the rotor 36 also rotates, and the movement of the alternator coil 38 that is close to the magnet 40 induces a current in the coil. The current is used to charge the battery pack 42 that supplies power to the electronics 44 of the device 10.

  The apparatus 10 includes a pump piston 46 that can reciprocate within a pump cylinder sleeve 48, and a pump piston seal 50 provides a seal between the pump piston and the cylinder sleeve 48. The piston 46 is connected to the eccentric member 32 by a connecting rod 52 that rotates with a large end bearing 54 held in place by an eccentric bearing plate 56. A compression chamber is formed between the piston 46, the sleeve 48, and the cylinder head 58 including the air filter 60 including the foam filter element 62. Piston 46, cylinder sleeve 48, seal 50, cylinder head 58, etc. form a pump that is configured to supply compressed air to tire 18. The connecting rod 52 of the pump piston 46 forms the first part of the pump drive system, and the eccentric member 32 forms the second part of the pump drive system. As will be described later, the pump drive system is configured to start the pump when the pressure of the tire 18 falls below a predetermined threshold.

  A pressure manifold 64 is provided and defines a number of flow paths, connectors, and the like. Three solenoid type pneumatic valves 66 are provided. Only one of them can be seen in FIG. These are controlled by the electronic device 44. As will become apparent from the following functional description, the operation of the pressure manifold 64 is substantially more fully described in PCT / IB2013 / 054732, except that it is not connected to the clutch piston. A manifold defining a cavity, two tire pressure hoses (from two tires 18), a solenoid valve 66, two shredder expansion valves, and a pressure port from the compression chamber of the pump to a common cavity in the manifold; It is sufficient to note that the is connected.

  Some of the ancillary features shown in FIG. 3 include an antenna 68 that allows the electronics 44 to communicate with an external device (such as a vehicle-mounted computer) and a wheel temperature / rotation speed sensor 70. . The rotational speed is determined through a Hall effect sensor that detects the rotation of the magnet attached to the stator 26. The part of the device 10 outside the rotor 36 (apart from the shredder expansion valve) is protected by a cover 72.

  In use, the entire apparatus 10 typically rotates with the wheel hub 12 apart from the pump shaft 28 and the stator 26. The eccentric member 32 and the rotor 36 also rotate with the hub 12.

  When the tire pressure of the tire drops below a predetermined pressure, direct current from the battery pack 42 is supplied to the coil 38 to generate an electromagnetic flux. The stator 26 is magnetized so as to resist rotation of the rotor 36 due to hysteresis characteristics in a magnetic field generated by the electromagnetic flux. Thus, the rotor 36, the coil 38, and the stator 26 function as a hysteresis type electromagnetic clutch except that the stator 26 functions as a hysteresis disk. This function is conventionally implemented by a “rotor”. When the clutch is engaged, the rotor 36 and the eccentric member 32 no longer rotate with the hub 12 but are kept fixed together with the stator 26.

  While the eccentric member 32 is kept fixed by the engagement of the clutch, the other part of the device 10 continues to rotate, and the connection is made by the relative rotation between the large end of the connecting rod 52 and the eccentric member 32. The rod 52 and the pump piston 46 reciprocate in the pump cylinder sleeve 48. In this way, the pump is activated to supply compressed air that is guided to the tire 18 before being inflated through the pressure manifold 64.

  When the tire pressure reaches a predetermined level, the tire pressure is disconnected from the manifold 64 and the current to the coil 38 is stopped, thereby disengaging the clutch and returning the device 10 to the normal state.

  In an alternative embodiment, instead of engaging the clutch by passing current from the battery pack 42 through the coil 38, the output of the coil is shorted so that the rotation of the coil in proximity to the magnet 40 is not Induces current in a closed circuit. These generate a magnetic force opposite to the rotation to hold the rotor 36 in a fixed state with respect to the stator 26. In order to release the clutch, the output from the coil 38 is easily released.

DESCRIPTION OF SYMBOLS 10 Apparatus 12, 12.1 Hub 16 Rim 18 Pneumatic tire 20 Wheel nut 22 Fixed hollow shaft 24 Wheel bearing 26 Stator 28 Pump shaft 30 Head 32 Eccentric member 34 Roller bearing 36 Rotor 38 Alternator coil 40 Alternator magnet 42 Battery Pack 44 Electronic equipment 46 Pump piston 48 Pump cylinder sleeve 50 Pump piston seal 52 Connecting rod 54 Large end bearing 56 Eccentric bearing plate 58 Cylinder head 60 Air filter 62 Foam filter element 64 Pressure manifold 66 Pneumatic valve 68 Antenna 70 Sensor 72 Cover

Claims (4)

An apparatus for supplying pressurized air to a rotating pneumatic tire,
(A) a pump that rotates with the tire during use and supplies pressurized air to the tire when the pump is activated;
(B) A pump drive system for starting the pump at the time of pressure loss of the tire,
(C) a first portion rotationally connected to the tire;
(D) a second part that rotates together with the first part when the pump is not operating and activates the pump when rotation with the first part is prevented, wherein the first and second parts A second portion, wherein the relative rotation drives the pump to supply pressurized air to the tire;
(E) An electromagnetic clutch including a first plate that cannot rotate and a second plate that rotates together with the second portion, and the first plate electromagnetically moves to the second plate when the clutch is engaged. An electromagnetic clutch connected to the first plate and preventing rotation of the first plate and the second portion;
A pump drive system including:
Including the device.   The apparatus of claim 1, wherein the clutch is a hysteresis clutch.   The apparatus according to claim 1, comprising a coil supported on one of the plates, a battery pack, and a switch for connecting the battery pack to the coil so that a current flows through the coil.   A coil supported on one side of the plate, a magnet supported on the other side of the plate, and rotation of the coil adjacent to the magnet induces a current in a closed circuit constituted by the coil. And a switch for short-circuiting the coil.

Images